The Pope is the head of the largest denomination of Christianity in the world. The Catholic Church has more than a billion members.

When the Pope makes a statement about any topic, the rest of the world listens. He plays a major role in the conversation on social issues from the church itself to politics.

Pope Benedict hand-picked a large portion of the currently serving Cardinals. They will be voting on the next Pope. This means Benedict's influence will carry through to the next Pope, even though he says he won't be involved in the selection process.

"One of the things he's best known for is rolling back some of the advances made during Vatican 2, to try and liberalize the church and bring the church into the modern era," said Miguel Delatorre, a professor with Iliff School of Theology in Denver.

The Archdiocese of Denver, like the rest of the world, was shocked to hear the news of Pope Benedict's resignation.

"I think people understand and admire that the Holy Father wants to make room for new enthusiastic leadership when he feels like his health is now allowing for that," Archdiocese Chancellor JD Flynn said. "It is a good choice."

The Archdiocese of Denver doesn't think this is the start of a new trend of Popes retiring, instead of spending the rest of their life in the role.

Delatorre says there's hope that it will be a new trend, to get new blood into the Vatican more often.